New Zealand First has revealed part of the policy platform it hopes will encourage older people to vote it back into a position of power - tax rebates on health insurance premiums for the elderly.

Party MP Andrew Williams has tabled a private member's bill which would allow those holding a SuperGold card, which is available only to those over the age of 65, a 25 per cent rebate against the premiums they pay on health insurance, subject to a maximum of $500 a year.

In recent years health insurance premiums have skyrocketed thanks to a mix of increased claims for things like knee and hip ops, as well as "medical inflation" which is the cost of things like surgeons' salaries, drugs, and equipment like prosthetics.

That's put an enormous strain on the wallets of superannuitants, many of whom have been downgrading their policies in a bid to keep their insurance in place.

Without medical insurance people have to rely on the state system, and that can mean a long and debilitating wait for operations like hip and knee replacements.

While tax rebates have been dismissed by the Government as too expensive, NZ First believes it is affordable. It has set out its thinking in the Affordable Healthcare Bill, and it would not just be pensioners able to claim tax rebates.

Under the policy, companies would also be exempted from paying fringe benefit tax (FBT) on any contributions they make to the cost of keeping their workers fit and healthy through subsidising health cover.

That, the bill says, is consistent with allowing companies to claim tax rebates against the ACC accident insurance premiums they pay, adding that Government should not be sending the "wrong message" to employers who wish to play a responsible role in their employee's health arrangements.

The New Zealand First policy is, the preface to Williams' bill claims, a way of encouraging more private spending on healthcare to bring it back into line with other developed countries.

"New Zealand's private health spending has fallen below the OECD average of 28 per cent of total healthcare spending. At about 16.5 per cent and downward trending, New Zealand's private healthcare spending compares adversely with Australia's private healthcare spending at 35 per cent," it said.

Southern Cross Healthcare, the largest health insurer in the country, has long supported tax rebates on premiums.